Alf.io
Open-source ticket reservation platform for events of any size
Overview
Alf.io is a full-featured, open-source event ticketing and reservation system written in Java. It supports paid and free events, multiple ticket categories, promo codes, check-in via QR code, and integrations with Stripe, PayPal, and Mollie for payments. Organizations can self-host it on any server running Java or deploy it via Docker, and a web-based admin panel handles the entire event lifecycle from creation to attendee check-in.
Where it falls short of Calendly
- No built-in recurring appointment booking (1:1 scheduling like Calendly)
- Mobile app for attendees is not provided; check-in relies on a separate web view
- Analytics and post-event reporting are basic compared to Eventbrite or Cvent
- Initial Java/PostgreSQL setup is heavier than typical SaaS onboarding
We list the gaps honestly so you can decide if the trade-off is worth owning your data.
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